Fish-trap

              Fish-traps or “pots”, as they are sometimes called, of various shapes and sizes are operated in Thai coastal waters.  According to their shape, three main groups can be distinguished: semi-cylindrical, rectangular and cylindrical traps.  The entrance to a trip is usually either funnel-shaped or wedge-shaped.  Small traps are about 55 cm long, 27 cm wide and 22 cm in height or diameter.  Large traps are about 200 cm long, 100 cm wide and 85 cm high.

              Rattan is traditionally the most widely used material for making trap frames.  This natural material is not only readily available but is also strong and pliable.  This last quality makes it particularly useful for building frames of cylindrical or semi-cylindrical traps.  Wood is used for frames of rectangular traps.  Bamboo is another commonly used material for traps.

              Nowadays, polyethylene netting is the main material for comparatively smaller traps, whereas the mesh of larger ones is made of steel wire.  Polyethylene nets with rhomboid mesh have mesh-size of about 4.5 – 12.01 cm.  The wire netting normally has hexagonal meshes, whose one leg (bar) is about 2.0 – 2.5 cm long.

              As many as 120 traps can be shot in the course of one operation.  Each trap has its own float and float-line, and each is shot separately from the others.  Small-sized traps are usually baited and are hauled daily.  Large traps, on the other hand, do not contain any bait and are kept on the bottom for several days continuously.  Sometimes the float-line is made shorter than the water depth so that it does not show on the water surface.  In this way the trap is more likely to remain in position until its owner returns to look for it.  In such a case fisherman must know the exact setting position of their traps, by means of the bearings of objects on land.

              The traps which have a short float-line and submerged floats are hauled by using a special method.  When the boat comes near the place where the trap is set, a fairly long line, about 50 m long and with sinkers attached at both ends, is shot to surround the float-line of the trap.  The float of the trap is large enough to be hooked by this surrounding long line, which is than used to pull the trap to the surface.